Another possibility is that the game file is loaded from a different folder than the main file and any files it loads are not being targeted properly as a result. So if the game file loads other files this is something to consider as well. When a Flash file is placed in an html page, it is as good as being in the same folder as that html page, so any files it loads need to be targeted accordingly... that goes for any files that embedded swf loads as well, such as your games.

All the files are in the same folder, and all games are just 1 swf file (no php, xml, external .as or subfolders).

About the other recomendation of using _lockroot... where should i place it? i have 3 frames (1, 2 and 3) with a stop action, and in another layer on frame 2, all the actionscript.

If i place the code on the frame with all the actionscript, this should be at the beginning of the code, or can i place it at any line? Or is it easier to place it in one of the other frames where i placed the stop action?

Setting the _lockroot property to true can be done 1) inside the swf game that you are loading (first frame would be best), or 2) can be done from the file doing the loading, but it has to be done after loading is complete, which means you need to use the MovieClipLoader class to determine when loading is complete.